Translation:
GAELELQUEJAS wrote:
Error HT201372 when downgrading macOS Sonoma to Monterey
I got bored of using macOS Sonoma, so I tried installing macOS Monterey and got the following error HT201372.
It tells me it can't open or install macOS from a newer version of macOS.
[Re-Titled by Moderator]
You will need to create a bootable macOS USB installer using the instructions in the following Apple article:
Create a bootable installer for macOS - Apple Support
If you have a 2018-2020 Intel Mac with a T2 security chip, then you will first need to modify the security settings to allow booting from USB by using the Startup Security Utility as explained in the following Apple article:
About Startup Security Utility on a Mac with the Apple T2 Security Chip - Apple Support
You will need to erase the disk before installing Monterey so make sure you have a good backup of all your data before erasing the system. Also, you may not be able to migrate/restore some items which use a library because the Sonoma library database structure may not be backwards compatible with the structure used by Monterey. Photo Library, Music Library, Video Library, and even possibly the Mail app library.
FYI, macOS Monterey is no longer supported by Apple nor by many third party app developers....even Ventura which is the OS just before Sonoma will be losing Apple support & security updates in a few months (these older operating systems can still be used, but some apps may start losing functionality....especially those accessing online resources).